U.S. Pat. No. 4,570,875, Buluschek, monitors the winding of a rope, or cable, by means of a motor, onto a wheel. He uses direct illumination.
U.S. Pat. No. 4,456,199, Seibert, monitors the winding of a strand-shaped winding material and provides computerized means for ascertaining at every instant the relative position of the spool respective the strand guide. Also this system differs in many aspects from that of the invention, and cannot be used with transparent optical fibers of the 0.3 mm diameter range: also this patent uses direct illumination.
U.S. Pat. No 4,410,147 Seiber, deals with a control device fro obtaining a uniform winding a strand shaped material, based on an electrical scanning device which detects the transition from a winding layer to the next one by detecting the step that is formed during such transition. Opto-electrical or acousto-electrical means are used.
U.S. Pat. No. 4,928,904, Watts, deals with the monitoring of the winding of an optical fiber, but his method is based on the introduction of light into the optical fiber, where it undergoes internal reflections, detecting the position of the illuminated portion of the fiber. The Watts Patent demonstrates in a clean manner that he did not arrive at the simple indirect illumination of the fiber, as is done according to the present invention, but resorts to the internal illumination of the fiber. He does not form a silhouette and does not use indirect illumination, and thus his monitoring is based on entirely different principles.